As detailed in the above-referenced U.S. Provisional Patent Application (Ser. No. 60/787,502), a process (utilized by the employer of the present inventor(s)) is utilized to neck a can, such as an aluminum can, or other stress-induced plastically deformable container. That is, a process exists where a diameter of an opening is reduced in size by drawing-out or lengthening (necking) the area of the container proximate the opening.
As a can (or other container) is necked, the opening takes on a waviness in shape (instead of being level and circular). The “wavy” portion of the container is referred to as “earing” (which is a condition caused by the continuous forming or necking of the container). Typically, the smaller the openings of the can with respect to its original size, the more reductions or necking operations that are required, and the wavier the top edge of a can becomes. Typically, the waviness is not a desirable feature, and, in fact, can cause various problems with subsequent can production operations, such as, for example, edge rolling and/or threading.